That's a pretty bold claim considering that (for instance) MAME's CPC emulation eats 25% of one CPU core (checked with vsync enabled). MAME might not be the fastest because they do a lot of the inter-chip-communication via function pointers, but they're also not idling around and the CPC emulation is quite accurate AFAIK. If you can point me to an emulator that's hundreds or thousands of times faster I'd really like to take a look, might steal some ideas ;)